Circuit panels or substrates are widely used in electronic assemblies. Typical circuit panels commonly include a dielectric element in the form of a sheet or plate of dielectric material having numerous conductive traces extending on the sheet or plate. The traces may be provided in one layer or in multiple layers, separated by layers of dielectric material. The circuit panel or substrate may also include conductive elements such as via liners extending through the layers of dielectric material to interconnect traces in different layers. Some circuit panels are used as elements of microelectronic packages. Microelectronic packages generally comprise one or more substrates with one or more microelectronic devices such as one or more semiconductor chips mounted on such substrates. The conductive elements of the substrate may include the conductive traces and terminals for making electrical connection with a larger substrate or circuit panel, thus facilitating electrical connections needed to achieve desired functionality of the devices. The chip is electrically connected to the traces and hence to the terminals, so that the package can be mounted to a larger circuit panel by bonding the terminals to contact pads on the larger circuit panel. For example, some substrates used in microelectronic packaging have terminals in the form of pins extending from the dielectric element.
Despite considerable efforts devoted in the art heretofore to development of substrates and methods for fabricating such substrates, further improvement would be desirable.